Generalize plan-issue runtime adapters and add installer flow

[graysurf]

Generalize plan-issue runtime adapters and add installer flow

Summary

Generalize plan-issue-delivery so runtime adapters are optional peer candidates across Codex, Claude Code, and OpenCode, and add an explicit plan-issue-adapter installer/sync/status CLI instead of implicit runtime setup.

Changes

• Refactor plan-issue-delivery runtime-role docs and prompts so the canonical contract stays on workflow_role, while Codex, Claude Code, and OpenCode are documented as equal adapter choices.
• Add runtime adapter templates for all three CLIs plus a new scripts/plan-issue-adapter entrypoint that supports install, sync, and status with dry-run by default.
• Add adapter installer tests, smoke coverage, and script documentation for the new explicit setup flow.

Testing

• PYTHONPATH=. pytest skills/automation/plan-issue-delivery/tests/test_automation_plan_issue_delivery.py skills/automation/plan-issue-delivery/tests/test_automation_plan_issue_delivery_adapter_installer.py tests/test_script_smoke.py -k 'plan_issue_delivery or plan-issue-adapter or test_script_smoke_spec' (pass)
• scripts/check.sh --entrypoint-ownership (pass)
• scripts/check.sh --all (pass)

Risk / Notes

• scripts/plan-issue-adapter intentionally defaults to dry-run; runtime config is only written when --apply is explicit.
• The Codex installer merges only managed plan_issue_* sections and leaves unrelated user config intact.
• The OpenCode installer merges only agent.plan-issue-orchestrator and preserves unrelated JSON keys.